Grinding wheel truing apparatus



p 5, 1939- c. c. ALVORD 2,171,516

7 v GRINDING WHEEL TRUING APPARATUS Filed I580. 10, 1938 2 SheetsrSheet 1 F v P52 f REVERSE PATH UFD/AMDNI/ 88 90 FASTSPEED 89 STARTING E. POSITION I: r 63 140 as 28 S 29 Sept. 5, 1939. c. c. ALVORD 2,171,516

' GRINDING-WHEEL mums APPARATUS I Filed Dec. 10, 1938 2 Sheets-Sheet2 Heal 51 2 Y A 2a 'CHA RLES. G. A LVURD Patented Sept. 5, 1939' v UNITED STATES PATENT orries 2,171,516 GRINDING WHEEL TRUING APPARATUS Charles C. Alvord, Worcester, Mass, assignor to Norton Company, Worcester, Mass a corpora.- tion of Massachusetts Application December 10, 1938, Serial No. 244,883

10 Claims. (01. 125-11) This invention relates to grinding machines, showing the path of movement of the truing tool and more particularly to a truing apparatus for during a truing operation. truing a plurality of spaced, different diameter The improved truing apparatus has been illusgrinding wheels. A trated in the drawings as mounted fixedly on top One object of the invention is to provide a of a wheel slide l which rotatably supports a simple and thoroughly practical truing apparatus wheel spindle carrying a plurality of spaced for truing a predetermined form on a grinding grinding wheels I2 and l3 of different sizes and element. Another object of the invention is to diameters. true a plurality of closely spaced cylindrical por- The wheel slide I0 supports a truing apparatus tions of different diameters on one or more grindframe or base M. An adjustable horizontally ing elements. Another object of the invention is arranged member I5 is pivotally connected by to provide an improved truing apparatus whereby means of a stud IS with the frame I4. An adjusta single truing tool is arranged to true a plurality ing screw threaded into a lug |8 projecting of spaced grinding wheels in a multi-wheel grindfrom the base |4 serves to adjust the member l5 ing machine. Another object of the invention is about its stud or pivot Hi to facilitate adjusting to-provide a truing apparatus for a multiple wheel the position of the member l5 relative to the base. grinding machine, in which a single truing tool A lock nut I9 serves to lock the screw I! in an adis traversed across the faces of a pl r l y f justed position. The member l5 may be clamped grinding wheels to true the same to predeterin adjusted position on the frame I4 by means of mined relative diameters. A further object of clamping screws which pass through elongated '20 the invention is to' provide an improved hydrauslots 26 in the lugs 21 on the frame I4 and are lically operated multiple wheel truing apparatus. screw threaded into the member l5. A dovetailed A further object'of the invention is to provide slideway 20 is formed integral with the member 'a power reciprocated, hydraulically actuated, cam l5 and is arranged to support a horizontally mov- 25 controlled truingtool which is arranged for move-. able slide 2| having a dovetailed slideway 22 95 "ment in a path successively to true either a form which mates with the dovetailed slideway 2|]. An on the periphery of a single grinding wheel or to adjustable tapered gib 23, interposed between the true a plurality of grinding wheels of different dovetailed ways 20 and 22, serves to take up lost diameters. Other objects will be in part obvious motion between the fixed and movable parts of or in part pointed out hereinafter. the slide. A screw 24 is provided to facilitate end- 30 The invention accordingly consists in. the feawise adjustment of the gib 23. tures of construction, combinations of elements, The horizontal slide 2| is provided with a verand arrangements of parts, as will be exemplified tically extending member 28 which is formed in the structure to be hereinafter described, and either integra t e ew fi y mounted 85 the scope of the application of which will be inthereto. The vertically extending portion 28 of dicated in the following claims. the horizontal slide 2| is provided withpa dove- In the accompanying drawings,.in which i tailed slideway 29 which ,supports a vertically shown one of various possible embodiments of the movable Slide 39 having a a n dovetailed Slidemechanical features of this invention, Way 3|. An us b e tapelfed gib 32 Serves to Fig 1 is a frontelevation of the improvd talze up lost motion between the dovetailed slide- 40 m apparatus mounted on a Wheel slide haw ways 29 and 3|,-and a screw 33 serves to facihtate ing the wheel guard removed; adlustment of h gib 3 Fig. 2 is a fragmentary diagrammatic view of A Second vertlcafny ranged Shde 5 supported by a dovetailed slideway 36 formed mthe the d control and Opemtmg a member 28. The dovetailed slideway 36 is proilmwmg the P and follower for conbr 011mg t .vided with a tapered gib 31 having an adjusting hit grmdmg wheel} screw 38. The slide 35 is preferably arranged so 3 1S rear elevatlon: on a lfeduced Scale that it may be moved vertically during the horiof the truing apparatus; zontal movement of theslide 2|. to Fig-41s fragmentary sectional view. on an The vertical slide 30 adjustably supports a enlarged 80916, taken ppr m y 011 the line truing tool holder which in the present case is 4-4 of Fig. 3; formed as a cylindrical bar 40 which is slidably Fig. 5 is a plan view of the improved truing keyed in an aperture 4i formed in a projection apparatus; and I 42 of the slide 30 by means of binding screws 65. Fig. 6 is a fragmentary diagrammatic view, 43 and 44, The truing tool support 40 carries vertically extending feed screw 5| is rotatably connected to the lug 56 and extends downwardly through a nut 52 carried by or formed integral with the vertically (arranged slide 38. The lower end of the feed screw 5| is journalled in 'a suitable bearing (not shown) formed within a casing 54 which is fixedly mounted to the vertical slide 28. A worm gear 55 meshes with a worm gear 56 supported on the inner end of a rotatable shaft 51. The shaft 51 is journalled in bearings (not shown) within the casing 54 andis provided at its outer end with a manually operable hand wheel 58. By adjustment of the manually operable wheel 58, the feed screw 5| may be rotated to adjust the position of the slide 38 relative to the vertically movable slide 35.

A power operated traversing mechanism is provided for producing a longitudinal traversing or reciprocating movement of the horizontally movformed integral'with or fixedly mounted on the end of the horizontal slide 2|. As fluid under pressure, is admitted either through a pipe or passage into a cylinder chamber 66 within the cylinder 66, or through a pipe or passage 61' into a cylinder chamber 68 within the cylinder 68, the

piston 6| is moved longitudinally to traverse or-- Y reciprocate the horizontally arranged slide 2| to traverse the truing tool 46 across the face of the grinding wheels I2 and I3. A

The admission of fluid under pressure to the cylinder chambers 66 and 68 is preferably controlled by a control valve 69 which in the present case is a rotary type valve. Fluid under pressure from a reservoir 16, preferably located within the base (not shown) of the machine, is pumped 'through .a pipe H by means of a motor driven pump 12 which forces fluid under pressure through a pipe 13 to the control valve 69. An

adjustable relief valve 14 is connected with the pipe line' 13 so that if the pressure within the hydraulic system increases over the desired and set pressure, the valve- 14' will exhaust excess fluid under pressure through a pipe l5 reservoir 18. I

In the position-of the valve 69 (Fig. 5), fluid under pressure passingthrough the pipe 13 enters a valve chamber 16 and passes out through, a pipe or passage 65 which admits fluid under pressure to the to the cylinder chamber 66 to cause the piston 6| and the longitudinally movable slide 2| carrying the truing apparatus 46 to move toward the right into the full line position as indicated in Fig. 1. During this, movement, fluid is exhausted from the cylinder chamber 68; through the pipe 61,

.- ment with the notch 91.

at the end of a lever I02 operating under the through a valve chamber 18, and out through a pipe 19 andpipe 88.

A speed regulating valve or variable speed throttle valve 8| is provided in the pipe 88 and serves to regulate the exhaust of fluid through the pipe 82 and thereby to regulate the traversing speed of the truing tool 46 across the operative face of the grinding wheels I2 and I3.

During the traverse of the truing tool, when it is not in operative engagement with the grinding wheel, it is desirable'to traverse the diamond and its supporting slides at a fast rate to facilitate a rapid dressing operation. A by-pass valve 83 is provided. This valve is preferably a piston type valve having valve pistons 84 and 85 formed integral with a valve stem 86. The outer'end of the valve piston 84 is provided with a conically shaped surface 81 which is arranged to serve as a folandthe endcover of the valve casing 83 (Fig. 2) .serves normally to hold the valve with the follower 87 in engagement with the cam 88. In the position of the valve 83 as shown in Fig. 2, fluid from the pipe 86 enters the valve chamber located between the valve pistons .84 and 85 and passes out through a passage 92 and a pipe 93 into the pipe 82,'thus by-passing the fluid around the throttle valve 8| so as to traverse the truing tool 46 and its supporting slides at a rapid rate. When the slide 2| traverses longitudinally relative to the arrow point 81, the follower rides down onto a low portion 94 on the cam plate 88, which serves to cut off the passage of fluid through the valve 83 by closing the port entering the passage 92, thus necessitating the exhaust of fluid through the needle valve 8| which is set to obtain the desired slow truing speed of the tool 46. The speed of movement of the truing tool 46 is again changed to a faster traversing speed at the other end of the stroke after the diamond or truing tool 46 traverses out of contact with the grinding wheels l2 and I3 being trued.

In truing a grinding wheel, it is desirable to reciprocate the truing tool across the surface of 'the wheel either one or more reciprocations for plate 98 supported by the rotary part of the valve 69. This movementof the valve starts the traversing movement of the slide 2| and the truing tool 46 toward'the left (Figs. -1 and 5) to traverse the truing tool 46 across the faces of the grinding wheels l2 and I3. The traversing movement of the truing tool, 46 and slide. 2| toward the left continues until an adjustably positioned collar or dog 99 carried by the slide 2| engages a cam surface "18 on the spring-pressed pawl 96, thereby withdrawing the pawl 96 from engageinfluence of gravity rocks the rotor oi thevalve 69 in a clockwise direction (Figs'l and .2) to reverse the position of the valve 69 and thereby 78 A weight |6| carried reverse the movement of the truing tool .46 and the slide 2| to traverse the same in the reverse direction across the peripheral faces of the grinding wheels I2 and I3, respectively. When the piston 6I engages the end of the cylinder 60 in its movement toward the right (Fig. 2), the truing tool 46 stops and remains in this position when the grinding operation is resumed.

In order that thetruing tool 46 may true a plurality of spaced grinding wheels of different diameters, such as a pair of spaced wheels I2 and I3, respectively, it is desirable to provide an actuating mechanism to move the slides 30 and 35 vertically. In truing a plurality of wheels which are closely spaced relative to each other and whose diameters are different 'from each other, it is desirable to provide an actuating mechanism for the truing tool 46 to rapidly raise or lower-the tool in a vertical direction when the truing tool 46 reaches a predetermined position in its traversing movement. A rotatable cam H is utilized to transmit a vertical movement to the slides 30 and 35. The rotatable cam H0 is supported on a shaft III which is supported on the vertical member 28 which is formed integral with the horizontal slide 2I. The outer end of the shaft III is supported in a bearing H2 formed integral with a bracket H3 which straddles the slide 35 and is fixedly mounted to the vertical member 28. A follower I I4 is fixedly mounted on the vertically'movable slide 35 and is arranged toiengage the periphery of the rotatable cam H0. The rotatable cam H0 is provided with a concentric portion H5 which, as illustrated in Fig. 2, is in engagement with the follower H4. The cam does not rotate during the passage of the truing tool 46 across the face of the grinding wheels. Consequently, with the concentric portion H5 it is not necessary to index the cam H0 to within very precise limits. As long as the follower II 4 engages the concentric portion H5, the diamond or truing tool 46 will be accurately positioned for truing the periphery of the grinding wheel I2. A similar concentric portion H6 is provided which is of a shorter radius to locate the truing tool 46 for truing the periphery of the grinding wheel I3, the difference in radii of the concentric portions H5 and H6 being equal to the difference in the radius of the two respective grinding wheel faces to be trued.

The cam I00 is preferably rotated rapidly to position the truing tool 46for its pass across the periphery of either the grinding wheel I2 or the grinding wheel I3. A hydraulically-operated cam turning mechanism is provided comprising a cylinder I having a slidably mounted piston I2 I. A piston rod I22 is connected at one end to the piston I2I and at its other end to a rack bar I23 which engages a small gear or pinion I24 which is fixedly connected to rotate with the cam H0. A guide I25- is provided to guide the rack bar I23 and maintain it in mesh with the gear I24.

A cam plate I26 is mounted on the rear of the truing apparatus'member I5 and is provided with a cam track I 2I'which is engaged by a squareshaped follower I28 which is either formed integral with or fixedly mounted on the lower end of the rack bar I23. The piston I2I and rack I23, therefore, cannot produce a rotary motion of the cam H0 while the truing tool 46 is travremains in the position illustrated in Fig. 2 with the concentric portion H5 engaging the follower H4. The parts remain in this position until the follower I28 travels along the cam track I21 into the position I28a so that it is free to travel in a vertical direction within the vertical portion I29 of the cam track I21. In this position of the parts at the start of the traversing operation, fluid under pressure from the pump I2 passing through the pipe I3 passes through a pipe I30, into a. chamber I3I of a control valve I32, and passes out through a pipe I33, into a cylinder chamber I34, to exert a downward pressure on the piston I2I which serves through the rack bar I23 to cause the cam II 0 to rotate in a clockwise direction to swing the concentric portion H6 of the cam H0 into engagement with tool 46 into position for truing the periphery of the grinding wheel I3. In this position, the follower I28.assumes the position I28?) and engages the lower horizontal portion of the cam track I21 which prevents further rotation of the cam H0. The fluid pressure within the chamber 68 serves to traverse the truing tool 46 and slide 2I toward the left to pass the truing tool 46 across the periphery of the wheel I3 to true thesame. This fluid pressure mechanism. 0perates in the reverse manner as the truing tool and slide are traversed in the opposite direction on the return stroke.

During the downward movement of the piston I2I, fluid within a cylinder chamber I40 exhausts through a pipe I4I, a, valve chamber I42, and out'through a pipe I43 and a throttle valve I44 and a pipe I45 which connects with the exhaust pipe 82 to return the exhaust fluid to the reservoir I0. The throttle valve I44 is provided to regulate the exhaust of fluid from the cylinder I20 and thereby to regulate the rate of movement of the truing tool 46 and the rotary cam H0 in shifting from one diameter of wheel to the other.

The valve I32 is preferably arranged in axial alignment with the valve 69 and a common valve stem I46 connects the two valves so that they are actuated simultaneously by either the control knob 95 or the weighted arm I 02.

On the return stroke of the truing tool 46, the valve I32 is shifted into the reverse position so that fluidunder pressure from the pump is admitted through the pipe I4I into the cylinder chamber- 'I40 to produce an upward movement of the pismovement of the truing tool 46 toward the left.

The truing tool traverses first at a rapid rate until it is about ready to contact with the periphery of the grinding wheel I2 whereupon the valve 83 cuts off the exhaust of fluid and fluid thereafter exhausts through the needle valve 8| to slow the traverse of the truing-tool 46 down the follower H4, thus rapidly lowering the truing to a slow truing speed. This speed continues until the follower I28 reaches the position I28a' (Fig. 2). The engagement of'the follower I28 7 with the vertical portion ms of the cam track I21 stops the longitudinal traversing movement of the truing tool and fluid under pressure passing through the pipe I33 into the cylinder chamber I34 causes a downward movement of the rack bar I23 to rotate the cam $1M in a clockwise direction which serves rapidly to lower the truing tool in a vertical direction into a position determined by the concentric portion Iii: of the cam' III), which position locates the truing tool 46 in position accurately to true the periphery of the grinding wheel I3. When the follower i28 reaches the position I282), the pressure still being on within the cylinder chamber 6%, the slow traversing movement again starts to traverse the truing tool 46 across the periphery ofthe grinding wheel l3. After the truing tool finishes its traverse across the periphery of the grinding wheel I3, the speed is again increased during its idle movement toward the left until the dog or collar 99 engages the cam face 31% to withdraw the pawl 96 from the notch 93. Withdrawal of of the pawl 96 releases the weighted arm M32 and the arm together with the valves to and i132- rotates in a clockwise direction to reverse the direction of flow of fluid within the system. The

return traverse of the truing tool M5 is then complated in the reverse order, the tool traversing across the face of the grinding wheel then rising vertically clue to actuation of the piston IN, and thentraversing across the periphery of the grinding wheel Iiafter which the truing tool continues its movement toward the right into an aoperative position and stops. The truing tool may be ad'iusted vertically before the truing operation is started or at any time during the truing operation, or at the left-hand end of its stroke, by rotation of the manually operable feed wheel 58.

all matter hereinbefore set forth or shown in the accompanying drawings is ,to be interpreted as illustrative and not in a limiting sense.

I claim: 4

1. In a .wheel truing apparatus, a truing tool, a longitudinally traversable truing tool holder, means to traverse said holder and truing tool across the peripheries of a plurality of grinding wheels, means including a rotatable cam and a follower to move said tool toward and from the wheel periphery to position the truing tool for truing a plurality of closely spaced grinding wheels, means to stop the traversing movement of the truing tool, and means automatically to rotate said cam automatically to repositionthe truing tool for truing an adjacent grinding wheel of different diameter.

2. In a grinding wheel truing apparatus, a truing tool, a longitudinally traversable truingtool v holder, means to traverse said holder across the ward and from the wheel periphery to position the truing tool for truing-successive wheels, and

, an interlock which serves positively to stop the V traverse of the truing tool and .to hold it sta- 'tionary until the rotation of the cam has repositioned the truing tool for truing an adjacent grinding wheel.

3. In a grinding wheel truing apparatus, a truing tool, a longitudinally traversable truing tool holder, means including a hydraulic piston and cylinder to traverse said holder and truing tool across the peripheral face of a. grinding wheel, means including a cam and a follower to move said tool toward and from the periphery of the grinding, wheel to true a predetermined shape ing tool, a longitudinally traversable truing tool holder, means including a hydraulic piston and,

cylinder to traverse said holder and truing tool across the peripheral face of agrinding wheel, means including a cam and a follower to move said tool toward and from the periphery of the grinding wheel to true'a predetermined shape thereon, means including a piston and cylinder operatively connected to actuate said cam rapidly to move the truing tool either toward or from the wheel periphery, and means including a track camand'a follower to govern and control the vmovement of said piston.

' 5. In a grinding wheel truing apparatus, a truing tool, a longitudinally traversable truing tool holder, means including a hydraulic piston and cylinder to traverse said holder and truing tool across the peripheral face of a grinding whee1, a rotatable cam-and a follower to move the truing .tool toward and from the periphery of the grinding wheel to true a predetermined shape thereon, means including a rack and pinion to rotate said cam, a fluid pressure piston and cylinder to actuate said rack and pinion, and means "including a track cam and a follower connected to move with said piston to govern and controlthe movement of the piston.

6. In a grinding wheel truing apparatus, a Iongitudinally traversable truing tool holder, means to traverse said holder and truing tool across the peripheral faces of a plurality of grinding 'wheels of different diameters, means including a rotatable cam and a follower to move said tool transversely toward and from the peripheries of said grinding wheel, said cam having spaced concentric portions thereon to position the truing tool for truing the peripheral faces of different sized wheels, and means including a piston and cylinder operatively connected to rotate said cam so as quickly to shift the truing tool either toward or from the periphery of the wheel so as to position it for successively truing different diameters thereon. 7. In a grinding wheel truing apparatus, a truing tool, a longitudinally traversable truing tool holder, means to traverse said holder and truing tool across the peripheral faces of a plurality of grinding wheels of different diameters, means including a rotatable cam and a follower to move said tool transversely toward and from the peripheries of said wheels, means including a rack and gear mechanism to rotate said cam, and means including a fluid pressure cylinder and piston operatively connected to move said rack so as to produce a rapid transverse movement of the truing tool either toward or from the peripheries of said wheels, said cam havinga plurality of paced concentric portions which serve to locate he truing tool for truing spaced grinding wheels.

8. In a grinding wheel truing apparatus, a trung tool, a truing tool holder, means to adjust he holder and tool relative to the vertical slide. vertically movable slide therefor. a horizontal ongltudinaily movable slide which supports said 'efrtical slide, means to reciprocate said horizontal slide so as to traverse the truing tool succeslvely across the peripheral faces of a plurality ii spaced grinding wheels or diiferent diameters, deans including a rotatable cam and a follower, 6' move said slide vertically to position the trung tool in operative relation with successive :rinding wheels, means including a rack and gear fiechanism to rotate said cam, and means inluding a fluid pressure piston and cylinder operai'vely connected to actuate said rack and gear nechanism to rotate said cam.

3. In a grinding wheel truing apparatus, a trung tool, a truing tool holder. means to adjust he holder and tool relative to the vertical slide,- .-"verticaily movable slide therefor. a horizontal ongitudinaily movable slide which supports said ertical slide. means including a fluid pressure perated piston and cylinder to reciprocate said qrizontal slide so as to traverse the truing tool uccessively across the peripheral races of a pluality of spaced grinding wheels of difl'erent diamitem, means including a rotatable cam and a ollower to move said slide vertically so as to poition the truing tool in operative relation with uccessive grinding wheels, means including a act and gear mechanism to rotate said cam; means including a fluid pressure operated piston and cylinder which are operatively connected to actuate said rack and gear mechanism, and means including a track cam and a follower which serves to govern and control the movement of said piston.

10. In a grinding wheel truing apparatus, a truing tool, a truing tool holder, means to adjust the holder and tool relative to the vertical slide, a vertically movable slide therefor, a horizontal longitudinaliy movable slide which supports said vertical slide, means to reciprocate said horizontal slide so as to traverse the truing tool successively across the peripheral facesof a plurality of spaced grinding wheels of diilerent diameters. means including a rotatablecam and a follower to move said slide vertically to position the truing tool in operative relation with successive grinding wheels, means including a rack and gear mechanism to rotate said cam. said cam having a plurality of spaced concentric portions for 10-- eating the truing tool in position to true spaced I wheels of different diameters, means including 

